Bleeding on dual antiplatelet therapy: real-life challenges

Dual antiplatelet therapy (DAPT) is recommended for patients presenting with acute coronary syndromes and patients undergoing coronary angioplasty with drug eluting stent implantation to prevent ischaemic recurrences.1 The advocated duration of DAPT for both these conditions is 1 year after the initial event. Standard DAPT includes a P2Y12 inhibitor either Clopidogrel, Prasugrel, or Ticagrelor in addition to aspirin. Due to inconsistent platelet inhibition observed with clopidogrel, most of the centres today use either Prasugrel or Ticagrelor as preferred P2Y12 antagonist. Platelet inhibition observed with these two agents is more consistent and stronger as compared with clopidogrel. However, DAPT carries a risk of bleeding while offering protection against ischaemic events like stent thrombosis.2 Since bleeding on DAPT is as an independent predictor of long-term outcome, it is important to identify patients who are at risk of bleeding. The recognized factors contributing to increased bleeding risk include advanced age >75 years, prior history of bleeding, heart failure, peripheral artery disease, hypertension, abnormal renal, or liver function and prior stroke. Other contributory factors include chronic steroid use, smoking, alcohol abuse, anaemia, and malignancy.3 The incidence of bleeding reported in ADAPT-DES registry was 6.2% at median time of 300 days following discharge.4 It is also known that almost two-thirds of the bleeding episodes occur from the gastrointestinal (GI) tract. Overall GI bleeding is estimated to occur in 1.2–2.4% patients undergoing coronary interventions. Identifying patients at higher bleeding risk prior to coronary intervention can help in reducing the occurrence of bleeding complications. The DAPT study developed a risk score to identify patients at higher risk of bleeding if DAPT is continued beyond 1 year.5 This score can be applied to patients who have tolerated DAPT up to 1 year following the initial event. Identifying patients at risk of bleeding at the initiation of DAPT can now be done using PRECISE-DAPT score, which is a simple score calculated from five simple variable such as age, creatinine clearance, haemoglobin, white-blood cell count, and previous spontaneous bleeding.6 Although there are no established norms for personalizing DAPT, use of this score in conjunction with the knowledge of coronary anatomy and the clinical condition may help in choosing appropriate therapy and its duration.7 We describe four case scenarios to highlight the bleeding issues related to DAPT and therapeutic decisions about interruption/continuation of antiplatelet agents in patients who suffer bleeding episode while receiving DAPT.